Chemical characterization and biological activity of an endemic Amaryllidaceae species: Galanthus cilicicus

The phytochemical investigation on Galanthus cilicicus Baker (Amaryllidaceae) led to the isolation of four alkaloids (tazettine 1, galanthamine 2, sanguinine 3, and haemanthamine 4). The alkaloid patterns of bulbs and aerial parts of G. cilicicus were also studied by gas chromatography/mass spectrometry (GC/MS). Twenty alkaloids were detected. In the aerial parts, among the detected alkaloids, haemanthamine and tazettine were the main alkaloids, whereas in the bulbs galanthamine and tazettine were predominantly found. A microplate assay modified from in vitro Ellman's method was used to determine the acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory potentials of the alkaloidal extracts prepared from the bulbs and aerial parts of G. cilicicus. The prepared extracts showed remarkable AChE and BuChE inhibitory activities. Since some Amaryllidaceae alkaloids have been reported to exert anti-inflammatory properties, we have also investigated the potentials of both alkaloidal extracts to inhibit a key feature of inflammation, i.e. the interaction of leukocytes and endothelial cells. Both extracts concentration dependently decreased the adhesion of a human monocytic cell line onto tumor necrosis factor-alpha (TNF-α) activated primary human endothelial cells. Moreover, the extracts lowered the surface expression of the endothelial adhesion molecule (ICAM-1), which mediates leukocyte-endothelial cell interaction.